Mushroom bullet



May 13 1924. 1,493,614

.1. A. DHCKERMAN MUSXIRDOM BULLET Filed sent. 1. 1920 WETNESS lNVENTOR JOHN A DICKERMAN ATTORNEY 1.4.9. shown.

Patented May 13, 1924.

UNITE SATES 1,493,614 PATENT oFFlcE.

JOHN A. DICKERMAN, F BRIDGEPORT, CONNECTICUT ASSIGNOB TO REMINGTON ARMS COMPANY, INC, A CORPORATION OF DELAW'ARE.

" MUSHROOM BULLET.

To all whom it may concern:

Be it known that 1, JOHN A. DICKERMAN, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and .15, State of Connecticut, have invented certain new and useful Improvements in Mushroom Bullets, of which the following is a specification.

The present invention relates to improvel9 ments in mushroom bullets and particularly to such bullets of the sharp-nosed or spitzer t" e.

il primary object is to provide a generally improved mushroom bullet of simple and 1? cheap construction having superior mushrooming qualities at various ranges and velocities.

It is a further object to provide such a bullet which is not easily deformed in the 2? magazine or in the barrel and which has substantially the same ballistic properties as metal jacketed bullets of the same type so that they may be used alternately wlthout sight adjustment.

Other objects and advantages of the 1nventio-n will become apparent from the following description of a preferred embodlment thereof described for purposes of illustration and shown in the accompanying drawings, in which Fig. l is a side elevation of a bullet embodying the present invention.

r Fig. 2 is a central cross section of the jacket and core, the tip being shown 1n elevation and Fig. 3 is a side elevation of the bullet tip.

The bullet preferred at present may be said to consist generally of the rigid tip 5, the jacket 6 and the soft metal core 7 as The rigid tip 5, preferably solid, may be made of brass, bronze, copper or aluminum or other fairly hard metal or al- 10y. It comprises the forwardly converging impact head 8 which is shaped to form a smooth continuation of the contour of the jacket, so that with the jacket it forms the contour of the bullet. The jacket 6 is preferably although not necessarily closed at the heel as by the wall 14 and in the form shown is generally cylindrical, converging forwardly to the point 15 where it forms a flush joint with the tip 5. The tip converges rearwardly from the point 15 forming the wedge 16 which merges at 16 into the anchor 17 which may be generally cylin- Application filed September 1, 1920. Serial No. 407,305.

drical. The core 7, which is formed of lead or similar soft metal, is entirely solid near the heel of the bullet but is formed with a cavity rearward of the anchor 17 and in alignment therewith.

When the bullet described above strikes an objective as the body of an animal it mushrooms in a very superior fashion. The tip 5 strikes first and as its velocity is reduced it is telescoped into the core and jacket, the wedge 16 serving to expand the front edge of jacket and core beyond the contour of the tip so that they engage the tissues of the animal and cause further eX- pansion and spreading of the jacket and core over the rear half of the bullet. This action is similar to that of the usual hollow point lead bullet. It forms an irregularly shaped mass having a total diameter several times that of the original bullet. The impact of this bullet therefore produces a disruption of the animal tissues over an area many times the cross sectional area. of the hole made by the ordinary bullet.

While it is desirable to allow the tip 5 to be quite easily set back into the bullet proper so asto assure mushrooming at lower velocities it is necessary to prevent this taking place too easily. As the bullet is accelerated in the barrel under a pressure which may exceed fifty thousand pounds per square inch the tip may set back on account of its inertia at the time of explosion unless the bullet is properly constructed. The cavity 20 is provided just behind the anchor 17 to permit the setting back of the tip at low velocities of impact. This greatly reduces the resistance to the setting back of the tip. This may be enhanced also by the conical formation of the heel 19 of the tip. In the construction shown, particularly when the forward portion of the jacket is weakened as at 6, the bullet will mushroom well at varying velocities but will not be deformed in the barrel. By locating the cavity 20 as shown it coincides more nearly with the center of gravity of the bullet and it therefore does not so materially disturb its balance as would be the case if the cavity were located near the point or the heel of the bullet.

lVhile the exact function of the cavity 20 is not absolutely known its presence seems essential to proper mushrooming. It does not provide a passage way for the tip 5 as it is too small to permit of the entry of the wedge portion. Experiments indicate that instead of serving as a passage way the cavity merely receives part of the core metal which is driven rearwardly by the wedge portion 16 and which metal flows more or less radially into said cavity. It will also appear that the wedge 16 has little or no wedging effect on the core itself as it appears to drive the core meta-l rearwardly substantially longitudinally.

In order to increase the resistance to the setting back of the tip 5 and to prevent the tip separating from the core and jacket it has been found advisable to form a depression in the anchor 17 which is preferably in the form of the annular depression or groove 18'. The core material lills this depression and so holds the tip in place. If desired the rear portion 17 of the anchor may be made of slightly larger diameter, as shown, in order to increase the firmness with which the tip is held in place.

If the tip 5 could be rotated relative to the bullet proper it would be quickly loosened in its socket and so unbalance the bullet and destroy its accuracy. To avoid this it is preferred to form the tip with suitable projections or depressions or both which may interengage with the bullet proper and so prevent relative rotation. In the form shown this is accomplished by the serrations 22 on any suitable part of the tip as in the groove 18.

The angular velocity of a. bullet at any point in its passage through the barrel is proportional to its linear velocity and its angular acceleration is proportional to its linear acceleration. The pressure acting on the bullet in the barrel therefore imparts a very high angular acceleration to the bullet while it is passing througl'i the barrel. On account of its inertia of rotation the tip 5 has a tendency to move forwardly without rotating and it would do so unless properly interlocked with the bullet proper. The tip would therefore enlarge its socket and so be loosened enough to injuriously affect the accuracy of the bullet. The interlocking provided by the serrations 22- effectually prevents this and it is thought improves the accuracy of the bullet by preventing this type of deformation in the barrel.

In the preferred method of manufacture of this bullet the jacket is drawn substantially cylindrical, with the heel closed. The core is inserted in the jacket and firmly seated by a punch which may simultaneously form a central cylindrical depression in the core. of a diameter corresponding to the largestdiameter of the cavity 20. The tip 5 is placed in a die having the shape of the finished bull-etand the jacket and core are forced into the die, whereby the forward part of the acket is wedged together, forcing the core metal to How forwardly and around the anchor 17 and wedge 16.

The above description of one embodiment of this invention is to be considered merely as illustrative, as many changes may be made therein by those skilled in this art which would be included within the meaning and range of equivalency of the following claims l. A mushrooming bullet comprising a soft metal core having an unfilled cavity located adjacent the center of gravity of the bullet, a. jacket surrounding said core, and a rigid tip having an exposed impacting head constituting a smooth continuation of the contour of the jacket and having a rearward edge seated against the end of the jacket and a rearwardly extending anchor aligned with said cavity.

2. A mushrooming bullet comprising a soft meta-l core having an unfilled cavity located adjacent the center of gravity of the bullet, a acket surrounding said core, and a rigid tip having an exposed impacting head constituting a smooth continuation of the contour of the jacket and having a. rearward edge seated against the end of the jacket and a rearwardly extending anchor aligned with said cavity, said anchor being formed with a core receiving depression.

3. A mushroon'iing bullet comprising a soft metal core having an unfilled cavity located adjacent the center of gravity of the bullet, a: jacket surrounding said core, and a rigid tip having an exposed impacting head constituting a smooth continuation of the contour of the jacket and having a rearward edge seated against the end of the jacket and arearwardly extending anchor aligned with said cavity, said core and anchor being formed with inter-engaging means for preventing relative rotation.

4:. A mushroom bullet, comprising a soft metal core, a jacket surrounding said core and a rigid tip having an exposed impact head constituting a smooth continuation of the contour of the jacket and having a rearwardly extending anchor imbedded in said core and inter-engaging means to prevent motion of the tip relative to the core and jacket, comprising an annular depression in said anchor and serrations formed in said depression.

As an article of manufacture, a tip for bullets comprising a forwardly converging impact head and a rearwardly extending anchor formed with an annular depression, and serrations in said depression.

6. As an article of manufacture, a tip for bullets comprising a forwardly converging impact head, a rearwardly extending anchor formed with serrations, and a rearwardly com-*erging portion between said head and anchor.

7. A mushroom bullet, comprising a soft metal core, a jacket surrounding said core and a rigid tip having an exposed impact head constituting a smooth continuation of the contour of the jacket and having a rear- 5 wardly converging portion seated against the end of said jacket and a rearwardly extending anchor imbedded in said core, and interengaging means to preventmotion of the tip relative to the coreand jacket, com 10 prising an annular depression in said anchor and serrations formed in said depression.

8. As an article of manufacture, a tip for bullets comprising a. forwardly converging impact head, a rearwardly extending anchor formed with an annular depression and provided with serrations in said depression, and a rearwardly converging portion between said anchor and said head.

In Witness whereof I have signed my name hereto this 30th day of August, 1920.

JOHN A. DICKERMAN. 

